There are occasional applications for a device having two interchangeable outer surfaces, the outer surfaces being interchangeable, where the interchange of surfaces is powered either manually or under power from an actuator.
Application for such a device may include toys, satellites or other devices having delicate equipment fixed to one of the two interchangeable outer surfaces. For example, a solar collector may have one side exposed for power collection and another side exposed during hailstorms. Similarly, a satellite may protect its solar arrays by exposing a bare surface until launch, after which the exterior surface inverts to expose the solar arrays.
Another application may include weather/climate dependent camouflage for remote sensors placed in cold-weather climates. Such a remote sensor may have need to interchange a green, brown, or mottled green-brown exterior with a white exterior during or after a winter storm to avoid visual detection. Other applications are also possible, including some discussed below.